exec-apoo: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/exec-apoo - from package: apoo

You may install the required package with command apt-get install {package}

Error in other languages:
exec-apoo: bevel nie gevind nie
exec-apoo: comandă negăsită
exec-apoo: comando não encontrado
exec-apoo: commande introuvable
exec-apoo: command not found
exec-apoo: käsku ei ole
exec-apoo: không tìm thấy lệnh
exec-apoo: komanda nerasta
exec-apoo: Kommando nicht gefunden.
exec-apoo: kommandot finns inte
exec-apoo: komut yok
exec-apoo: nie znaleziono polecenia
exec-apoo: níor aimsíodh an t-ordú
exec-apoo: no se encontró la orden
exec-apoo: no s'ha trobat l'ordre
exec-apoo: opdracht niet gevonden
exec-apoo: parancs nem található
exec-apoo: perintah tidak ditemukan
exec-apoo: príkaz nenájdený
exec-apoo: příkaz nenalezen
exec-apoo: команда не найдена
exec-apoo: командата не е открита
exec-apoo: 命令找不到
exec-apoo: コマンドが見つかりません